First histological observations on the incorporation of a novel nanocrystalline hydroxyapatite paste OSTIM(® )in human cancellous bone

BACKGROUND: A commercially available nanocrystalline hydroxyapatite paste Ostim(® )has been reported in few recent studies to surpass other synthetic bone substitutes with respect to the observed clinical results. However, the integration of this implantable material has been histologically evaluated only in animal experimental models up to now. This study aimed to evaluate the tissue incorporation of Ostim(® )in human cancellous bone after reconstructive bone surgery for trauma. METHODS: Biopsy specimens from 6 adult patients with a total of 7 tibial, calcaneal or distal radial fractures were obtained at the time of osteosynthesis removal. The median interval from initial operation to tissue sampling was 13 (range 3–15) months. Samples were stained with Masson-Goldner, von Kossa, and toluidine blue. Osteoid volume, trabecular width and bone volume, and cortical porosity were analyzed. Samples were immunolabeled with antibodies against CD68, CD56 and human prolyl 4-hydroxylase to detect macrophages, osteoblasts, and fibroblasts, respectively. TRAP stainings were used to identify osteoclasts. RESULTS: Histomorphometric data indicated good regeneration with normal bone turnover: mean osteoid volume was 1.93% of the trabecular bone mass, trabecular bone volume – 28.4%, trabecular width – 225.12 μm, and porosity index – 2.6%. Cortical and spongious bone tissue were well structured. Neither inflammatory reaction, nor osteofibrosis or osteonecrosis were observed. The implanted material was widely absorbed. CONCLUSION: The studied nanocrystalline hydroxyapatite paste showed good tissue incorporation. It is highly biocompatible and appears to be a suitable bone substitute for juxtaarticular comminuted fractures in combination with a stable screw-plate osteosynthesis

Evaluation of a novel nanocrystalline hydroxyapatite paste Ostim® in comparison to Alpha-BSM® - more bone ingrowth inside the implanted material with Ostim® compared to Alpha BSM®

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to evaluate the performance a newly developed nanocrystalline hydroxyapatite, OSTIM^®following functional implantation in femoral sites in thirty-eight sheep for 1, 2 or 3 months. Ostim^®35 was compared to an established calcium phosphate, Alpha BSM^®.</p> <p>Methods</p> <p>Biomechanical testing, μ-CT analysis, histological and histomorphological analyses were conducted to compare the treatments including evaluation of bone regeneration level, material degradation, implant biomechanical characteristics.</p> <p>Results</p> <p>The micro-computed tomography (μCT) analysis and macroscopic observations showed that Ostim^®seemed to diffuse easily particularly when the defects were created in a cancellous bone area. Alpha BSM^®remained in the defect.</p> <p>The performance of Ostim was good in terms of mechanical properties that were similar to Alpha BSM^®and the histological analysis showed that the bone regeneration was better with Ostim^®than with Alpha BSM^®. The histomorphometric analysis confirmed the qualitative analysis and showed more bone ingrowth inside the implanted material with Ostim^®when compared to Alpha BSM ^®at all time points.</p> <p>Conclusions</p> <p>The successful bone healing with osseous consolidation verifies the importance of the nanocrystalline hydroxyapatite in the treatment of metaphyseal osseous volume defects in the metaphyseal spongiosa.</p

Higgs Boson Mass and New Physics

We discuss the lower Higgs boson mass bounds which come from the absolute stability of the Standard Model (SM) vacuum and from the Higgs inflation, as well as the prediction of the Higgs boson mass coming from the asymptotic safety of the SM. We account for the three-loop renormalization group evolution of the couplings of the SM and for a part of the two-loop corrections that involve the QCD coupling alpha(s) to the initial conditions for their running. This is one step beyond the current state-of-the-art procedure ("one-loop matching-two-loop running"). This results in a reduction of the theoretical uncertainties in the Higgs boson mass bounds and predictions, associated with the SM physics, to 1-2GeV. We find that with the account of existing experimental uncertainties in the mass of the top quark and alpha(s) (taken at the 2 sigma level) the bound reads M-H >= M-min (equality corresponds to the asymptotic-safety prediction), where M-min = (129 +/- 6) GeV. We argue that the discovery of the SM Higgs boson in this range would be in agreement with the hypothesis of the absence of new energy scales between the Fermi and Planck scales, whereas the coincidence of M-H with M-min would suggest that the electroweak scale is determined by Planck physics. In order to clarify the relation between the Fermi and Planck scales a construction of an electron-positron or muon collider with a center-of-mass energy similar to (200 + 200 GeV) (Higgs and t-quark factory) would be needed

Human periodontal ligament fibroblasts stimulated by nanocrystalline hydroxyapatite paste or enamel matrix derivative. An in vitro assessment of PDL attachment, migration, and proliferation

Item does not contain fulltextWe determined the effects of soluble or coated nanocrystalline hydroxyapatite paste (nano-HA) and enamel matrix derivative (EMD) on proliferation, adhesion, and migration of periodontal ligament fibroblasts (PDLs). Cultured PDLs were stimulated with nano-HA paste or EMD in a soluble form or were coated to the surface of cell culture dishes. Proliferation of PDLs on coated nano-HA and EMD was quantified by various methods including bromodeoxyuridine (BrdU) incorporation and Western blot. Cell migration was investigated in a modified Boyden chamber. The surface integrin profile of PDLs was determined using an integrin-specific ELISA, and integrin-specific signaling was measured by immunoblotting of phosphorylated focal adhesion kinase (FAK). Coated nano-HA stimulated PDL proliferation to a larger extent as compared with coated EMD. PDL migration towards a nano-HA or EMD gradient was more efficiently mediated by soluble EMD as compared with nano-HA but vice versa, adhesion of PDLs to compound-coated dishes was more effectively mediated by nano-HA as compared with EMD. Mechanistically, majorly integrin alpha5beta1-mediated adhesion of PDL and both coated compounds mediated a significant increase in FAK activation though to a different extent. Current findings offer two different modes of action for EMD and nano-HA paste. EMD efficiently acts as a chemoattractant in its soluble form, while nano-HA paste effectively serves as a synthetic extracellular matrix component in its coated form. Our findings suggest that EMD and nano-HA paste display different molecular characteristics and apply alternative routes to mediate their beneficial effects on periodontal tissues